Truck-ladder.



PATENTED JUNE 4, 1907.

T. HAINES. TRUCK LADDER. APPLIOATION FILED An, s, 1906.

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lg'nesses:

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PATENTED JUNE 4, 1907. T. HAINES. TRUCK LADDER.

APPLICATION FILED APR.5,1906.

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No. 855,771. PATENTED JUNE 4, 1907. T. HAINES} TRUGK LADDER.

APPLICATION FILED APR.5,1906.

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THE mamas PETERS ca, WASHINGTON, n. c.

PATENTED JUNE 4, 1907.

T HAINES TRUUK LADDER. APPLICATION FILED APR. 5

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THOMAS HAINES, OF ST. LOUIS, MISSOURI.

TRUCK-LADDER.

Specification of Letters Patent.

Patented June 4, 1907.

Application filed April 5,1906. Serial No. 809,979-

To (all 11/72/0711 it may concern:

Be it known that I, THOMAS I'IAINES, a citizen of the United States, anda resident of the city of St. Louis and State of Missouri, have inventeda new and useful Improvement in Truck-Ladders, of which the following isa specification.

My invention relates to truck ladders, and especially to truck laddersfor fire department service; and it has for its principal obj ects tofacilitate the raising and lowering of the ladder; to hold said ladderin its elevated position; and other objects hereinafter more fullyappearing.

My invention consists in the parts and in the arrangements andcombinations of parts hereinafter described and claimed.

In the accompanying drawings, which form part of this specification, andwherein like symbols refer to like arts wherever they occur, Figure 1 isa si e elevation of the truck ladder; Fig. 2 is a plan View thereof;Fig. 3 is an enlarged sectional view of a portion of the elevatingmechanism; Fig. 4 is a plan detail view of the hoisting cable and pistonconnection; Fig. 5 is a vertical section of the forward part of thetruck on line 55 of Fig. 2 with the ladder in its normally loweredposition; Fig. 6 is a vertical section of the forward part of the truckon line 55 of Fig. 2 with the ladder in its elevated position; Fig. 7 isa front end elevation of the truck ladder; Fig. 8 is an enlarged detailview showing the ladder holding mechanism in elevation Fig. 9 is adetail view showing a portion of the ladder holding mechanism in sideelevation; Fig. 10 is a detail view of one of the operating cranks.

Upon the forward part of a wheeled truck 1 is mounted a base plate 2 onwhich is pivotally mounted a turntable 3. Two upright frames a aresecured on the turntable and constitute supports for a horizontal axle 5upon which are pivotally mounted a main section 6 of the ladder and thetwo main lifting booms 7 therefor. Said axle is further supported at itsends by means of braces 8.

Mounted in suitable journal bearings pro vided therefor on the uprightframes 1s a main winding shaft 9, which is equipped at its ends withhand levers or cranks 10 for actuating. Upon the main shaft, is a pinion1 1 which meshes with a gear 12 upon a shaft 13 which is journaled inbearings provided therefor on the upright frames 4. The shaft 13 has aratchet wheel 14 fixed thereon in position for a pawl 15 loosely mountedon the main shaft to engage with. Said shaft 13 is also provided at eachend with winding drums or sheaves 16. These winding drums have cables 17fastened to their hubs, and the groove or space between the endshoulders of each drum is approximately equal to the diameter of thecable. In consequence of this arrangement the effective diameter of thedrum increases with each turn thereof for the purpose hereinafterstated. The cables respectively pass over pulleys 18 that are journaledin downwardly extending arms mounted on the main lifting booms forwardof their axle; and thence said cables extend, respectively, through saidlifting booms 7, which are tubular, and are secured at their other endsto links 19 mounted in said booms, respectively. In order to provide forthe mounting of said links 19 each of the main lifting booms is slottedlengthwise, and through each slot extends the arm 20 upon which the linkis pivotally mounted.

Thearms are respectively mounted on the ends of secondary lifting booms21 whose forward ends are pivotally connected to the upright frames,respectively, on the, turntable. In order to secure the greatestleverage action, the point of connection of the secondary lifting boomsto the turn table should be distant as far as practicable from the pointat which the main lifting booms are pivoted thereon. For this reason,the main lifting booms are pivoted at the upper por tion of the uprightframe and the secondary booms are pivoted at the bottom of said frame.

In order to give stability to the ladder when in its elevated position,the axle upon which it is mounted is preferably arranged above thecenter of the turntable, the booms being connected to the rearmostportion of the upright frames.

In order to gain leverage, the main lifting booms have downwardlyprojecting arms 22 which constitute their connection to the main axle:And the front ends of said booms extend forwardly of the main axle. Thewinding drums are so located that in the initial lowered position of theladder, the line of pull will make a high angle to the line extendingthrough the main axle and the axis of the pulley 18, and so that suchangle will increase to a right angle in the early stage of lifting saidladder.

In order to secure the ladder at such elevation as may be desired, thedownturned arms 'by which the booms are mounted on the axle are extendeddownwardly past the axle and are provided with perforated hubs. Througheach of these hubs extends a bolt 23 headed at one end andscrew-threaded at the other end. The portion near the head of the boltis flattened and fits in a slot 24 provided therefor in the uprightframe, said slot being a circular are having the axle for a center.

Upon the projecting screw-threaded end of the bolt is a large handwheel33 screwthreaded to engage therewith. When it is desired to fasten theladder at any position, the hand wheel is screwed home to firmly clampthe downturned arm to the frame. When it is desired to change theadjustment of the ladder, the hand wheel is unscrewed.

Each of the links 19 is secured to a sliding member 25 arranged insideof the tubular boom and mounted on the end of a piston rod 26. Thepiston head 27 works in an elongated cylinder 34 mounted on and inalinement with the tubular boom. This elongated cylinder has anair-admission port near its rearmost or outermost end, and into thisport leads a pressure pipe 28 which is arranged alongside of the boomand at its forward end communicates by means of a flexible hose 29 withan air storage tank 30 located on the turntable. Communication from theair tank to the cylinder is controlled by means of a turncock 31, orother suitable valve.

One or more cross-pieces 32 are mounted on and connect together the rearends of the main lifting booms and brackets are mounted on and securethe ends of the cylindrical extensions of said main booms to the mainsection of the ladder. The cross-pieces constitute a cradle upon whichrests the main section of the ladder.

The operation of the construction thus far described is as follows:Normally the parts are in the lowered position,as shown in full lines inFig. 1. In order to raise the ladder by air pressure the turncock 31 isopened, whereupon air from the pressure tank passes through the pipe 28and enters the outer or rear end of the cylinders. The pressure of theair thus admitted into the cylinders is transmitted through theirrespective pistons and piston rods to the links which are pivotallysecured to the secondary booms, and the pressure thus exerted swingssaid secondary booms upwardly and with them the ladder which is thusraised to the desired position. In order to raise the ladder by manualpower, the operator exerts his force upon the handcrank, and this forceis transmitted through the pinion on the crank shaft and through thegear which meshes therewith to the shaft of the winding drums, andthence through the cables thereon to the said links 19. In the initialposition of the parts, the effective radius of the winding drum is smallin com parison' with the gear wheel on the drum shaft, in consequence ofwhich the maximum power is applied at the beginning of the operation. Asthe lifting movement progresses, the effective radius of the drum isincreased by the thickness of the cable, so that the velocity of thelifting movement progressively increases with a corresponding decrease,however, of the force applied to the link 1.9. In the initial positionof the parts, the cables exert a leverage action tending tolift the mainboom. This leverage action is due to the arrangement of the pulleysforward of the main axle; and by reason of the fact that such pulleysare located above the main axle, the leverage continues through aconsiderable angular movement of the lifting operation. During theelevation of the main booms, the clamping bolt travels along in thecircular are provided therefor on the upright frames; and when the boomshave arrived at the desired postion, the hand wheels 33 are turned tofirmly clamp the depending arms of said booms to their respective sideframes. The pawl 15 on the main shaft cooperates with the ratchet torevent unintentional lowering of the lad er. In order to prevent thesudden lowering of the ladder, the rear or outermost portion of each ofthe cylinders is provided with a strong helical spring 35 which abuts atone end against the piston and at its other end against a bearing plate36 provided therefor at. the rear end of the cylinder. The position ofthis bearing plate or backstop is made adjustable by means of ascrew-bolt 37 which works in a threaded hole provided therefor in thehead of the cylinder and which is manipulated by means of a hand wheel38 on its outer end.

In order that the drivers seat 39 may be out of the way when the ladderis in a raised position, two downwardly projecting arms 40 are rigidlysecured to the forward end of the main section and pivotally connectedto the rear of the seat. To the front portion of the seat are pivotallysecured links 41 which are pivotally mounted on the main shaft 9. Theselinks are of such length as to maintain the seat in a substantiallyhorizontal position when the ladder is in its normal lowered position.I/Vhen the ladder is raised, the arms move downwardly and inwardly aboutthe axle 5, carrying the seat inwardly with them. I

The foot rest 42 is also arranged to be placed out of the way. Said footrest is pivotally mounted on the turn-table and'is held in normalposition by a link 43. This link is pivotally attached to the foot restat one end and has a hook or loop at its other end. The link rests uponthe shaft 9, whereby it is free to slide thereon rearwardly but has itsforward movement limited by the engagement of the hook with said shaft;and in this forward position, the link serves as a tie to hold said footrest in proper position.

The hub of the hand crank, which is arranged to slide on the shaft 9,has its outer end portion formed into a toothed clutch member adapted toengage a counterpart consisting of a toothed sleeve 44 fixed on the endof the shaft. The hub is provided with a spring-pressed pin 45 adaptedto fit into a circumferential groove provided therefor in the shaft 9 atthe point occupied by the pin when the clutch members are interlocked;in consequence of which arrangement the hub is locked against accidentaldisengagement. The locking pin has a projecting portion arranged formanipulation. By pulling out the spring pin, the hand crank is free tobe shifted inwardly on the shaft and be moved out of the way when theladder-actuating mechanism is not in use.

The ladder is composed of a main section and one or more extensionsections mounted thereon; and in other respects the truck ladder isprovided with the usual equipment.

Obviously, my device admits of divers modifications without departingfrom my invention, and I do not wish to be restricted to the specificconstruction hereinbefore described.

\Vhat I claim as my invention and desire to secure by Letters Patent is:

1. A truck ladder comprising a truck, a turntable mounted thereon, aladder and main and secondary lifting booms pivotally mounted on saidturntable, said booms having a sliding connection, and means forshifting said sliding connection, said means comprising cylindersmounted at the ends of the main booms and connected with a source ofpressure and having pistons connected to said sliding connection.

A truck ladder comprising a truck, a ladder and main and secondarylifting booms pivotally mounted thereon, said booms having a slidingconnection, means for shift-ing said sliding connection comprising acable connected to said sliding connection, and an operating means forsaid cable, mounted on said truck, and additional means for shiftingsaid connection comprising cylinders mounted on said main lifting boomand connected with a source of pressure and having pistons connected tosaid sliding connection.

3. A truck ladder comprising a truck, a ladder pivotally mountedthereon, means for raising and lowering said ladder and a shiftable scatpivotally mounted on said truck and secured to said ladder whereby whensaid ladder is raised, said seat is moved behind the ladder.

4. A truck ladder comprising a truck, a ladder and main and secondarylifting booms pivotally mounted thereon, said booms hav ing a slidingconnection, means for shifting said sliding connection, said meanscomprising cylinders mounted on said ladder and connected with a sourceof pressure, pistons connected to said sliding connection and springsarranged within said cylinders.

5. A truck ladder comprising a truck, side frames mounted on said truck,a structure including a ladder pivotally mounted on said side frames,means for raising and lowering said pivotal structure, arms fixedlysecured to said pivotal structure, and clamps for releasably holdingsaid arms to said side frames, whereby said pivotal structure can besecured in its elevated position.

6. A truck ladder comprising a truck, a ladder pivotally mounted on saidtruck, a main lifting boom secured to said ladder, a secondary liftingboom having a sliding connection with said main lifting boom, means formoving said sliding connection, a compression spring carried by saidmain boom and adapted to exert pressure upon said sliding connection,and an adjustable abutment for said spring.

7. A truck ladder comprising a truck, a ladder pivotally mounted on saidtruck, a main lifting boom secured to said ladder, a secondary liftingboom, a sliding member on said main lifting boom and having a pivotalconnection with said secondary lifting boom, means for moving saidsliding member, said means comprising a cylinder having communicationwith a source of pressure, a piston in said cylinder, said piston beingconnected to said sliding member, a compression spring between saidpiston and an adjustable abutment in said cylinder, and an adjustingscrew for said abutment extending to the outside of said cylinder,whereby the tension of said spring may be varied.

8. A truck ladder comprising a truck, a frame mounted on said truck, aladder pivotally mounted on said frame, a tubular main. lifting boomsecured to said ladder and having an arm near one end, said arm beingpivotally secured to said frame with its pivot in axial alinement withthe pivot of said ladder, a pulley mounted at the end of said main boomforward of itspivot, a secondary lifting boom pivotally mounted on saidframe, a sliding member mounted in said tubular main frame, said slidingmember having a pivotal connection with the outer end of said secondaryboom, a cable having one end secured to said sliding member, and passingover said pulley at the forward end of said main boom, and having itsopposite end secured to a winding drum beneath said pulley, and meansfor operating said drum.

9. A truck ladder comprising a truck, and a ladder, a tubular mainlifting boom con nected to said ladder, and a secondary lifting boom,said ladder and said lifting booms being pivotally mounted on saidtruck, and said tubular main boom being longitudinally slotted andhaving a slidable member therein, and said secondary boo'm having apivotal connection with said slidable member, and means to move saidslidable member to raise and lower said ladder.

10. A truck ladder comprising a truck, a turntable mounted on saidtruck, a ladder, a tubular main lifting boom pivotally mounted on saidturntable and connected to said ladder, a secondary lifting boompivotally mounted on said turntable, said tubular main boom having alongitudinalslot formed therein, a slidable member in said tubular mainboom, said slidable member having a pivotal connection with saidsecondary boom, and a cable having one end secured to said slidablemember and its opposite end. secured to and adapted to be wound about awinding drum.

11. A truck ladder comprising a truck, a turntable mounted on saidtruck, side frames mounted on said turntable, a pair of tubular mainlifting booms pivotally mounted on said side frames, a ladder carried bysaid main booms, a secondary lifting boom pivotally mounted. on saidturntable in operative relation to each of said tubular main booms,slidable members in said tubular main booms, pivotal connections betweensaid slidable members and said secondary booms, cables connecting saidslidable members to winding drums, operating means common to saidwinding drums, whereby said winding drums can clutch member on saidshaft, and also having a spring-pressed pin adapted to enter saidcircumferential groove when said engagement is effected. I

13. A truck ladder comprising a truck, a ladder pivotally mountedthereon, and means for raising and lowering said ladder, said meanshaving a power shaft and said power shaft having a clutch member on itsouter end portion, a crank slidably mounted on said power shaft, saidcrank having a clutch portion adapted to engage the clutch member onsaid power shaft, and means for releasably holding said crank with saidclutch portions in locked engagement, said releasable holding meanspermitting said crank to be moved inwardly on said shaft out of the way.

Signed. at St. Louis, Missouri, this 31st day of March, 1906.

THOMAS HAINES.

